Automatic slack take-up for chains.



A. K. TERNSTEDT. AUTOMATIC SLACK TAKE-UP FOR CHAINS.

Patented 10011121916.

APPLICATION FILED JAN. 25, I913.

WITH/E8858 ALV 1K. TERNSTEDT, OF NEW YORK, N.Y., ASSIGNOR T0 PERFECTWINDOW REGULATUR COMPANY, OF NEW YORK, N. ii, A CORPORATION OF MAINE.

AUTQMATIC SLACK TAKE-UP FOR. CHAINS.

Specification of Letters Patent.

Patented Dec... T2, T9116,

tinalappllcatton filed December 19, 1911, Serial No. 6%,759. Divided andthis application filed. January 25, 1913. Serial No. 744,116.

To all whom it may concern:

Be it known that l[, ALVAR K. TnRNs'rnD'r,

.a subject of the King of Sweden, and a resident of New York, in thecounty of New York and State of New York, have invented certain new anduseful Improvements in Automatic Slack Take-Ups for Chains, of which thefollowing is a specification.

My present invention relates to means for taking up slack in drivingchains and has for its object to provide simple and efiective means forautomatically taking up the slack and stretch in sprocket chains.

The particular merit attached to the invention is that it at all timeskeeps the chain taut without the necessity of changing the position ofthe sprockets over which it passes or providing other means for manuallytaking up the slack which exists or may develop under usage. It alsopermits the chain to stretch without subjecting it to extra tension. Bythus providing means for automatically keeping the chain taut at alltimes -any rattle of the chain against the sides of a casing in which itmay be located is avoided.

The :invention is particularly useful when employed with the chaindrives usually'used in mechanism for raising and lowerin windows but itwill be understood that t e invention"is of general application and notlimited to use with window operating apparatus or apparatus of anyparticular type. Its usefulness and eficiency is particularly noticeablewhen employed with the chain drives of window raising and loweringmechanismand particularly when used in moving vehicles as the drivingmechanism is mounted in a mall thin space in which, if the chain is theleast particle loose, the chain will strike against the side of thecasing and make the use of such mechanism annoying, if not prohibitive,in moving vehicles such as automobiles, boats, &c.

By utilizing this invention the slack in the chain is at all timesautomatically taken up as the chain stretches and at the same time theslack take-u device in no way interferes with the e cient drivin of thechain or with its smoothness in passing over any of the sprockets it maybe compelled to pass over.

To these ends the invention costs in the improved automatic take-up torchains hereinafter more particularly described and then specified in theclaims.

In the accompanying drawings, Figure 1 illustrates a side elevation of achain drive having my invention applied thereto. Fig. 2 is a similarview showing the chain in a difierent position with relation to thesprockets. Fig. 3 is an enlarged view of that portion of the chain towhich the invention is applied.

The uses to which the invention may be put being universal it is deemednecessary to illustrate it merely as applied to an ordinary sprocketchain passing over driving and driven sprocket wheels, the chain beingused in any connection and for any of the uses to which they are ormight be applied. 5 indicates a driving chain of any suitableconstruction and preferably consisting of a plurality of links pivotedtogether and so formed as to be'engaged by and pass over the teeth ofthe sprocket wheels 6 and 7.

,sprocket 6 imparts the power to the chain,

and power may be applied thereto in any manner.

Two of the chain links or the connectors for the links located at anydesired distance apart are provided with hooks or fingers 23 and 24s. A.helical tension spring 25 is secured at each end to the 'hooks 23 and24L, so that any slack which might exist in the chain is taken up by thespring drawing the links together, the links between the hooks orfingers 23 and 24 merely buckling slightly and the chain is therebyalways maintained in a uniform taut condition. I It will be obvious, asillustrated in Fig. 2, that the spring take up in no manner interfereswith the operation of the chain in passing over the teeth of eitherrocket.

It will be understood that various modifications in the manner ofapplying and carrying out the invention may be resorted to Withoutdeparting from the spirit thereof as expressed in the appended claims.

1 This application isa division of my prior application for windowoperating device filed Dec. 19,1911, Serial No. 666,759.

What claim as my invention is: I

1. it. driving chain comprisin'pivotally secured to each other, securedto two of said 1t and a sp coectt I pass, supplemental linksorconnectors pivotally secured to the links, hooks projecting from two ofsaid connectors and a tension spring having its ends secured to saidbooks 15 as and for the purpose described.

4. A sprocket driving chain comprising links pivotally connectedtogether, hooks laterally projecting from said chain remote from eachother and off-set from the link pivots and a spring connected to theends of 20 said hooks whereby the links between the hooks are maintainedin a taut condition.

Signed at New York in the county of New York and State of New York this24th day of January, A. D. 1913.

ALVAR K. TERNSTEDT.

' Witnesses:

F. B. TOWNSEND, K. M. MCMAHON.

